Devices which allow an infant to exercise its legs and practice walking have been proposed in the past. For instance, U.S. Pat. Nos. 451,128; 1,437,179; 1,469,436; and 3,049,350 disclose devices which permit a baby to walk in a circular path on or about a substantially stationary base. However, none of these devices is adapted to permit the baby to turn around or change its field of view while seated, thereby inhibiting the ability of the baby to interact with its surrounding environment while simultaneously walking or otherwise exercising its legs.
U.S. Pat. No. 839,681 discloses a baby walker in which a seat is slidably mounted on guide rails supported on a stationary frame. A baby seated in the seat can walk from one end of the guide rails to an opposite end on a fastboard or treadway. Such a device, however, is adapted for unidirectional travel only. That is, once the baby reaches the end of the treadway, the seat must be returned to the other end, thereby requiring assistance from older children or adults. Also, the baby cannot turn around or change its field of view while seated.
U.S. Pat. No. 875,377 discloses a baby walker in which a seat is rotatably mounted on a carriage adapted to move back and forth along a pair of support rods. A baby seated in the seat can walk from one of the support rods to the other end on a platform. Once the baby reaches the opposite end of the platform, he or she can turn the seat around and then walk back to the other end. Because the baby actually walks in a rectilinear fashion along the platform, the baby walker is, out of necessity, comparatively large and cumbersome. Although the mobility of the baby walker is enhanced by trucks (i.e., roller assemblies) provided at the bottom of the walker, such mobility poses a potential hazard in that the walker can be accidentally or unintentionally moved close to stairs or dangerous appliances, such as stoves and heaters.
U.S. Pat. No. 3,127,170 discloses a children's play table with a chair attached to a base. The chair can rotate about the central vertical axis of the table. However, because the chair is secured to a horizontal support rod by screws, the chair is prevented from rotating or spiraling about an axis of rotation passing through the center of the chair. Also, while an infant seated in the chair is able to pull and push the chair around the table, the infant can not actually walk while seated in the chair.
To overcome the disadvantages and shortcomings of the devices described above, the inventors herein have, in the past, obtained a number of patents on inventions having the common objective of providing an infant with the ability to practice walking in or along a predefined and controlled location or path, while simultaneously changing its field of view to orient itself to and interact with the surrounding environment. For instance, U.S. Pat. No. 4,743,008 discloses an infant exerciser having a seat which is rotatably supported in a central opening of an annular tray and a treadmill assembly which is suspended below the seat. An infant placed in the seat is thus able to move its legs in a walking motion on the treadmill and is able to change its field of view by rotating the seat relative to the tray. U.S. Pat. Nos. 5,085,428; 5,211,607; and 5,302,163 all relate to infant exercisers having a stationary frame in the form of a circular tray and an infant seat attached to the frame such that it can be revolved around the tray in an orbital manner. The seat can also rotate about its own axis of rotation, whereby an infant who is in the seat can walk along a circular path and/or turn in place.